1. Field of the Invention
The present invention relates to novel derivatives of N-substituted flavone-8-carboxamides represented by the formula (I): ##STR3## wherein R.sub.1 represents a hydrogen atom, a methyl group or an ethyl group; R.sub.2 represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom or a nitro group; R.sub.3 represents a hydrogen atom or a lower alkyl group; k represents 0, 1, 2, or 3; m represents 0 or 1, X and Y, which must be different, represent a hydrogen atom or a methyl group; A represents an amino group having the formula ##STR4## wherein R.sub.4 and R.sub.5, which may be the same or different, represent a lower alkyl group or a cyclic amino group together with the nitrogen atom and with or without an oxygen atom; R.sub.6 represents a lower alkyl group and n represents 2 or 3; which have an excellent effect for removing the impediments to urination (dysuria), non-toxic pharmaceutically-acceptable salts thereof, and process for preparation thereof.
The present invention also relates to pharmaceutical compositions containing the derivatives of the formula (I) and further to a method of treating a patient having an impediment to urination therewith.
2. Description of the Prior Art
As no therapeutical agent having a specific effect for removing impediments to micturition has been known, it has been necessary hitherto to employ, for purposes of eliminating impediments to urination, the available antispasmodics or tranquilizers. Recently it has been found that Flavoxate, of the chemical formula (II); ##STR5## possesses an activity for treatment of dysuria in practice (Merck Index, 9th Edition, 4012; U.S. Pat. No. 2,921,070). The compound of the prior are is, however, unsatisfactory for clinical use because of its poor effect and lower stability. The compound administrated per os is hydrolyzed in the digestive tract to a less active free carboxylic acid having the formula (III); ##STR6##